The use of radiation to treat medical conditions comprises a known area of prior art endeavor. For example, radiation therapy comprises an important component of many treatment plans for reducing or eliminating unwanted tumors. Unfortunately, applied radiation does not discriminate between unwanted structures and adjacent tissues, organs, or the like that are desired or even critical to continued survival of the patient. As a result, radiation is ordinarily applied in a carefully administered manner to at least attempt to restrict the radiation to a given target volume.
Radiation-treatment plans typically serve to specify any number of operating parameters as pertain to the dynamic administration of such radiation dosings with respect to a given patient. For example, many treatment plans provide for exposing the target volume to possibly varying dosages of radiation from a number of different directions.
Such radiation-treatment plans typically presume any number of metrics regarding the target volume and/or other organs and tissues in the vicinity of the target volume. Examples of such metrics include, but are not limited to, such things as the size, shape, and orientation of external and/or internal portions of a given organ. These metrics are sometimes developed for a particular patient by referring to previously-obtained x-rays, computed tomography data, and so forth and other times by referring to historical data for other patients or as gleaned from atlases of such content.
Unfortunately, even the best radiation-treatment plan can be rendered less viable or even unusable when the patient's presumed physical circumstances change over time. As one simple example in these regards, a given patient's bladder may have a very different size from day to day (or during any given day) as a function of the volume of currently-retained urine. Many such variations are difficult or even impossible to predict.
Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.